Excretion and Osmoregulation Notes
Waste :- anything excess quantity called as Waste .
Excretion :- Elimination of the west across the cell membrane called as excretion .
Osmoregulation :- To maintain the balance of water and salt in the body .
Homeostasis :- Internal environment constant called as homeostasis .
Mode of Excretion
1. Ammonotelism :- The elimination of nitrogenous waste in the form of ammonia called as ammonotelism .
E.g. :- fish
Those organism shows the process of ammonotelism called as ammonotelic organism .
The site of production of ammonia is liver .
For removal of 1 g ammonia needs about 300 to 500 ml of water .
2. Ureotelism :- The elimination of waste in the form of urea called as Ureotelism .
Those organism shows the process of Ureotelism called as ureotelic organism .
The urea is produce by ornithine urea cycle.
The site of production of Urea is mitochondria of liver cell .
Example :- Mammals, Cartilaginous fish ( shark and rays )
For removal of 1mg urea it require 50 ml of water .
3. Uricotelism :- Elimination of waste in the form of uric acid is called as uricotelism .
Those organism shows the process of uricotelism called as uricotelic organism .
The site of production of uric acid is in liver and partially in kidney.
The uric acid is produced by inosinic acid pathway.
Example :- Land snail, Reptiles
Uricotelism is a type of adaptation for conservation of water in desert.
4. Guanotelism :- simulation of waste into the form of guanine in called as Guanotelism.
Those organism shows the process of guanotelism called as guanotelic organism.
For removal of morning there is little water required or sometime no water is required.
Human Excretory System
Those system carries Excretion and Osmoregulation in human known as human excretory system.
The human excretory system consists of
1. Pair of kidney
2. Pair of adrenal gland
3. Pair of ureter
4. Urinary bladder
5. Urethra
Kidney ( structure of kidney )
Human kidneys are mesodermal in origin.
Doctor of kidney called Nephrologist
The branch which deals with a study of kidney called as Nephrology
Kidney is made up of millions of Nephrons.
The structural and functional unit of kidney is nephron.
Location of kidney
Each kidney are situated on either side of Oarta and vertebral column.
Kidney extent from 12th thoracic vertebra and 3rd lumbar vertebra.
In a pair of kidney, right kidney slightly lower than the left kidney because presence of liver.
Shape of kidney
The kidneys bean shaped. The weight of kidney in male is 150 g and female is 135 g.
Histological kidney consists of two region.
1. Renal cortex :-
a) Renal cortex present at upper side of Nephron.
b) It is dark red in colour.
c) It consists of manphingies is body.
2. Renal medulla :-
a) Renal medulla present at lower side of nephron.
b) It is light red in colour.
c) The millions of nephrons compact together up to 6 to 20 conical projections called as Renal Pyramid.
d) Each pyramid has a wide base attached to the cortex and narrow apex directed towards an inner space called as renal papillae.
2. Renal capsule :- The protective covering of kidney called as Renal Capsule.
a) It is shock absorber.
3. Columns of Bertini :- Extension of renal pyramid from renal cortex to renal medulla called as columns of Bertini.
4. Ureters :-
a) Pipe which conduct the urine from kidney to urinary bladder called as Ureter.
b) They are about 25 to 30 cm long and 10 mm in diameter.
c) They is a urine with the help of peace peristaltic movement or contraction.
d) The ureter is made up of epithelium tissue.
5. Urinary bladder :-
a) A Temporary storage unit of urine called as urinary bladder.
b) They store urine about 500 ml 1000ml.
6. Urethra :-
a) An opening where urine are release outside the body called as Urethra.
b) Urethra shows separate opening in Female.
c) In male Urethra is also called as Urogenital track.
Working of kidney
1. The renal artery receives blood from heart and transferred to a afferent Arteriole.
2. Afferent Arteriole receives blood from renal artery but blood is Oxygenated and Impure.
3. Afferent arteriole passes blood to the bed network of capillaries called Glomerulus.
4. On the surface of capillaries there is a presence of minute pores and pores are impermeable to blood and permeable to plasma.
5. Hence impermeable blood goes to the site of efferent arteriole and from efferent arteriole to renal vein and finally to the heart.
6. The diameter of afferent arteriole is more than efferent arteriole this difference in diameter creates pressure called as Hydrostatic pressure.
7. The nephron can be divided into two regions.
a) Bowman 's capsule :- about like structure called as bowman's capsule.
It collects plasma from minute pores. The plasma consists of two things is essential and nonessential material.
b) Renal tubule:- The Renal tubular from the base of Bowman's capsule the connection between this is called neck.
8. PTC :- Just near the neck the tubule is highly coiled and this region is called as proximal convoluted tubule.
9. Junction where absorption of glucose takes place.
10. They goes at the side of Henle's loop. Henle's loop consists of two region.
a) Descending loop of Henle's
b) Ascending loop of Henle's
12. The particular turn called as vesa recta.
vesa recta means counter current effect.
Physiology of excretion
1. Chemical Process :- it takes place in liver and includes deammination and ornithine urea cycle.
2. Mechanical Process :-
This process takes place in kidney and includes
A) Ultrafiltration
B) Selective Reabsorption
C) Tubular Secretion
A) Ultrafiltration :-
1. The filtration of blood under hydrostatic pressure through semipermeable membrane in manphingies body.
2. Ultrafiltration operates with three types of pressure
a) GHP [ Glomerular Hydrostatic Pressure ]
It is develop glomerulus due to difference in diameter of afferent and efferent arteriole.
The GHP 55 mmHg.
b) BCOP [ Blood Colloid Osmotic Pressure ]
In developing glomerulus due to plasma protein specially albumin protein.
The BCOP is 30 mmHg.
c) CHP [ Capsular Hydrostatic Pressure ]
Developing women capsule due to presting Fluid.
B) Selective Reabsorption :-
1. The useful substances are reabsorb by glomerulus filtration called as selective reabsorption.
2. About 99% of glomerular filtration reabsorb by selective reabsorption.
3. On the basis of amount of reabsorption of substances are divided into three categories.
a) High Threshold Substance :- the substance are totally absorbed from glomerulus filtrae. E.g. :- glucose
b) Low Threshold Substance :- The substance are reabsorbed only up to small extent are called low threshold substance.
c) Non - Threshold Substance :- The substance which are not reabsorb at all called as non - threshold substance.
C) Tubular Secretion :- The secretion of waste, non - essential excess substance from particular capillaries network into tubular fluid is called as tubular secretion.
Composition of urine
1. Amount :- 1.5 to 2 liter per day.
2. Nature :- Acidic
pH of urine also depends upon the diet when diet is vegetarian then the pH is basic or alkaline when the diet is non-vegetarian then the pH is acidic.
3. Colour :- Pale Yellow ( In Summer )
Colourless ( In Winter And Rainy Season )
4. Smell of urine is aromatic due to presence of urinode.
Kidney Failure
Inability of kidney to carry excretion and osmoregulation called as kidney failure.
Causes of kidney failure
1) Accident
2) Blood Pressure
3) Diabetes
4) Bacterial infection , etc
Two types of kidney failure
1) Acute Kidney Injury ( AKI ) :-
a) Acute kidney injury occurs suddenly.
b) Acute kidney injury is temporary and reversible.
Causes
a) Dehydration
b) Accident
Treatment
a) With the help of medicine
b) Surgery
2) Chronic Kidney Disease ( CKD )
a) This disease is progressive.
b) This is permanent and irreversible.
Causes
Blood pressure and diabetes
Treatment
Dialysis and kidney transplant
Kidney stone
The crystal of salt and calcium may be solid for insoluble in water
Nephrolithiasis :- Stone present inside the kidney.
Urolithiasis :- The stone are present at the site of urinary track.
Ureterolithiasis :- The stone present at the site of ureter.
Symptom
1) Server pain in back
2) Problem in urination
3) Sometime blood appears in urine
Treatment
1) Removal of stone by Surgery
Prevent :- Drink more and more water
Dialysis
-- Loosening of waste with the help of solution.
-- Dialysis is depend upon diffusion phenomenon.
-- At dialysing tube minute sopres are present.
Kidney Transplant
1) Donor
a) Identical Twins
b) Dissimilar Twins
c) Cadveric Donor
d) Closely relative
2) Recipient
It is also called as patient.
Criteria For kidney Transplant
1) Blood group should match
2) HLA- Human Lucocyte Antigen
3) Special type of genetic marker those are present on the surface of WBC ( it should be match ).
4) Antibody test
Regulation of kidney
The function of the kidneys regulated by Hypothalamus, Juxtra Glamorular Apparatus and Heart.
a) Hypothalamus part of brain.
b) Juxta Glomerular Apparatus it is a special type of cell those are present on the surface of kidney.
Role of kidney in Osmoregulation
1) Where there is shortage of water.
2) Where there is excess of water.
Some disorder of kidney.
1) Uremia :- The amount of urine present inside the blood.
Range :- 0.001 to 0.003 %
Uremia Range in blood :- 0.005 %
2) Nephritis :- Inflammation in glomerulus.
Cause :- Mechanical injury and Bacterial infection
Accessory Excretory organ
1) Skin :- Human skin is a thick in permeable. It shows presence of two types of glands.
a) Sweat gland :- It help in thermoregulation.
b) Sebaceous gland :- They secretes oily substance called sebum.
2) Lungs :- They Excrete the volatile substance like CO2 in H2O which are produced during respiration, most of the water is used for metabolic process and access is thrown out in the form of water vapour and CO2 is along the expired air.
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